The shapes one sees in cloud formations can be as revealing as an inkblot test which is why there’s something undeniably Freudian about calling these clouds mammatus clouds or “breast clouds.”

Forming under the main body of other cloud types, mammatus clouds are pockets of air and water caught in another storm’s down draught. Mammatus are often called “supplementary clouds” as they are not clouds in their own right. They are usually paired with cumulonimbus thunderclouds and can indicate severe storms and tornados. Cumulonimbus clouds contain the ice crystals which frequently produce hail stones and torrential rain. Here in the United States, mammatus clouds are often seen during warmer months in the midwest or back east. But they can be found all over the world. Mammatus may be smooth or lumpy and may be opaque or semi-transparent. The phenomenon lasts no more than five to ten minutes.